Structuring in liquid alkanes between solid surfaces : force measurements and mean-field theory

Measurements have been made of the solvation forces between mica surfaces in the even-numbered n-alkanes from hexane to hexadecane. In all cases the force law is qualitatively very similar, characterized by a decaying oscillatory function of distance, as occurs for simple isotropic liquids. The spacing between successive minima in the force does not increase with carbon number, and is comparable to the width of a linear alkane molecule rather than its length or any average diameter. This suggests that the alkanes have some tendency towards a parallel orientation near the mica surfaces. The measurements give no indication of any strong repulsive component expected from mean-field theories of higher alkanes or polymers. The results of one such theory are presented, and the reasons for its failure to match the experimental data are discussed.

The determination of the local conditions for void initiation in front of a crack tip for materials with second-phase particles

A procedure is proposed to determine, for second-phase particles near a crack tip, the maximum particle stresses at the moment of void initiation by either particle fracture or particle/matrix interface separation. A digital image analysis system is applied to perform a quantitative analysis of corresponding fracture surface regions from stereo image pairs taken in the scanning electron microscope. The fracture surface analysis is used to measure, for individual particles, the crack tip opening displacement at the moment of void initiation and the particle location with respect to the crack tip. From these data, the stress tensor at the moment of void initiation is calculated from the Hutchinson–Rice–Rosengren (HRR) field theory. The corresponding average local stresses within the particle are evaluated by a non-linear Mori–Tanaka-type approach. These stresses are compared to estimates according to the models by Argon et al. [A.S. Argon, J. Im, R. Safoglu, Metall. Trans. 6 (1975) 825] and Beremin [F.M. Beremin, Metall. Trans. 12 (1981) 723]. The procedure is demonstrated on an Al6061–10% Al2O3 metal matrix composite.

Within and against performativity : discursive engagement in adult literacy and basic education

The field of adult literacy and basic education (ALBE) has undergone dramatic changes in recent years with the advent of labour market programs, accreditation, competency-based assessment and competitive tendering for program funds. Teachers' working conditions have deteriorated and their professional autonomy has been eroded. ALBE has been increasingly instrumentalised to fulfil the requirements of a marketised economy and conform to its norms. The beliefs and value systems which traditionally underpinned the work of ALBE teachers have been reframed according to the principle of 'performativity' and the demands of the 'performative State' (Lyotard, 1984: 46, Yeatman 1994: 110). The destabilisation of teachers' working lives can be understood as a manifestation of the 'postmodern condition' (Lyotard 1984; Harvey 1989): the collapse of the certainties and purposes of the past; the proliferation of technologies; the impermanence and intensification of work; the commodification of knowledge and curricula; and the dissolving of boundaries between disciplines and fields of knowledge. The critiques of the modernist grand narratives which underpin progressivist and critical approaches to adult literacy pedagogy have further undermined the traditional points of reference of ALBE teachers. In this thesis I examine how teachers are teaching, surviving, resisting, and 'living the contradictions' (Seddon 1994) in the context of struggles to comply with and resist the requirements of performativity. Following Foucault and a number of feminist poststructuralist authors, I have applied the notions of 'discursive engagement' and 'the politics of discourse' (Yeatman 1990a) as a way of theorising the interplay between imposed change and teachers' practice. I explore the discursive practices which take place at the interface between the 'new' policy discourses and older, naturalised discourses; how teachers are engaged by and are engaging with discourses of performativity; how teachers are discursively constructing adult literacy pedagogy; what new, hybrid discourses of 'good practice' are emerging; and the micropractices of resistance which teachers are enacting in their speech and in their practice. My purpose was to develop knowledge which would support the reflexivity of teachers; to enrich the theoretical languages that teachers could draw upon in trying to make sense of their situation; and to use those languages in speaking about the dilemmas of practice. I used participatory action research as a means of producing knowledge about teachers' practices, structured around their agency, and reflecting their standpoint (Harding 1993). I describe two separate action research projects in which teachers of ALBE participated. I reflect on both projects in the light of poststructuralist theory and consider them as instances of what Lather calls 'within/against research' (Lather 1989: 27). I analyse written and spoken texts produced in both projects which reflect teachers' responses to competency-based assessment and other features of the changing context. I use a method of discourse mapping to describe the discursive field and the teachers' discursive practices. Three main configurations of discourse are delineated: 'progressivism', 'professional teacher' and 'performativity'. The teachers mainly position themselves within a hybridising 'progressivist /professional teacher' discourse, as a discourse of resistance to 'performative' discourse. In adapting their pedagogies, the teachers are in some degree taking the language and world view of performativity into their own vocabularies and practices. The discursive picture I have mapped is complex and contradictory. On one hand, the 'progressivist /professional teacher' discourse appears to endure and to take strength from the articulation into it of elements of performative discourse, creating new possibilities for discursive transformation. On the other hand, there are signs that performative discourse is colonising and subsuming progressivist /professional teacher discourse. At times, both of these tendencies are apparent in the one text. Six micropractices of resistance are identified within the texts: 'rational critique', 'objectification', 'subversion', 'refusal', 'humour' and 'the affirmation of desire'. These reflect the teachers' agency in making discursive choices on the micro level of their every day practices. Through those micropractices, the teachers are engaging with and resisting the micropractices and meanings of performativity. I apply the same multi-layered method of analysis to an examination of discursive engagement in pedagogy by analysing a transcript of the teachers' discussion of critical incidents in their classrooms. Their classroom pedagogies are revealed as complex, situated and eclectic. They are combining and integrating their 'embodied' and their 'institutional' powers, both 'seducing' (McWilliam 1995) and 'regulating' (Gore 1993) as they teach. A strong ethical project is apparent in the teachers' sense of social responsibility, in their determination to adhere to valued traditions of previous times, and in their critical self-awareness of the ways in which they use their institutional and embodied powers in the classroom. Finally, l look back on the findings, and reflect on the possibilities of discursive engagement and the politics of discourse as a framework for more strategic practice in the current context. This research provides grounds for hope that, by becoming more self-conscious about how we engage discursively, we might become more strategic in our everyday professional practice. Not withstanding the constraints (evident in this study) which limit the strategic potential of the politics of discourse, there is space for teachers to become more reflexive in their professional, pedagogical and political praxis. Development of more deliberate, self-reflexive praxis might lead to a 'postmodern democratic polities' (Yeatman 1994: 112) which would challenge the performative state and the system of globalised capital which it serves. Short abstract Adult literacy and basic education (ALBE) teachers have experienced a period of dramatic policy change in recent years; in particular, the introduction of competency-based assessment and competitive tendering for program funds. 'Discourse politics' provides a way of theorising the interplay between policy-mediated institutional change and teachers' practice. The focus of this study is 'discursive engagement'; how teachers are engaged by and are engaging with discourses of performativity. Through two action research projects, texts were generated of teachers talking and writing about how they were responding to the challenges, and developing their pedagogies in the new policy environment. These texts have been analysed and several patterns of discursive engagement delineated, named and illustrated. The strategic potential of 'discourse polities' is explored in the light of the findings.

The mediatization of the knowledge based economy : an Australian field based account

This paper presents an empirical account of mediatization from a Bourdieuian perspective, based on the development of a number of new concepts, such as cross-field effects and the rescaling of such effects as linked to processes of globalization. Built on an Australian empirical case relating to educational policy and the knowledge based economy, this paper argues that mediatization can be understood in relation to the cross-field effects of different fields of journalism on subsequent fields, which have their genesis in forms of practice that cross different social fields. Specifically, the case analysis details interactions between the field of print journalism and the field of policy over the course of an Australian science capability review, chaired by the then chief scientist, Dr Robin Batterham, which led to Australia adopting a national version of the knowledge economy. The empirical case also leads us to consider the impact of both global and national fields of journalism on fields of educational policy in relation to mediatization.

Sharpening the focus of force field analysis

The purpose is to explore the inherent complexity of Kurt Lewin's force field theory through applied analysis of organizational case examples and related methods. The methodology applies a range of tools from the consultancy research domain, including force field analysis of complex organizational scenarios, and applies bricolage and corroboration to emerging discoveries from semi-structured interviews, author experience, critical reflection and literature survey. Findings are that linear representation of internal and external forces in organizational applications of field theory does not fully explain the paradox of inverse vectors in the forces of change. The force field is not an impermeable thing; instead, it morphs. Examples of the inverse principle and its effects are detailed and extended in this analysis. The implications of the research are that force field analysis and related change processes promoted in organizational change literature run the risk of missing key complexities. The inclusion of the inverse principle can provide enhanced, holistic understanding of the prevailing forces for change. The augmentation of the early work of Kurt Lewin, and extension of previous analyses of his legacy in the Journal of Change Management and elsewhere, provide, in this article, change analysis insights that align well with current organizational environments.

Standardising differences? Theorising 'identities' and pedagogical approaches to working with diversity

‘Race’, socio-economic status, gender and ethnicity are theorised as fluid, dynamic and interconnected categories of identity within post-structural theories. Understanding identities as socio-culturally constructed offers opportunities to think differently about how teachers and teacher education students position themselves and are positioned within these discourses. In Australia, where the teaching profession is overwhelmingly Anglo-Australian (Rizvi 1992; Santoro et al, 2001), mono-lingual and of middle-class background, Australian students are becoming far more linguistically and culturally diverse. Since engagement with teachers who ‘know’ their students, (Delpit, 1995) and the communities from which they come is a major predictor of successful educational outcomes, the growing disparity between teachers’ and students’ cultural and classed experiences is of concern. While teacher education programs focus on developing the attributes in new graduates to work productively with difference, the actualities of doing so are problematic.

This paper reviews some current Australian, North American and United Kingdom approaches to working with student teachers’ constructs of self in terms of ethnicity, ‘race’ and class in order to problematise taken-for-granted ideas of ‘normal’. It considers debates that surface around ‘individuality’ versus ‘collective’ differences; additionally, some of the resistances and dilemmas that emerge when ‘white’, middle class students are asked to rethink their own positionality are examined. Questions regarding what constitutes productive ways to teach inclusive and transformative pedagogies are raised in light of current theory and practice.

Bringing Bourdieu to policy sociology : codification, misrecognition and exchange value in the UK context

The task of social scientists is to find ways of investigating and understanding the social, political and economic world, in order to offer insights into everyday and public life in the past, present and future. Bourdieu’s tool kit offers a particular way of theorizing the rules, narratives and self-held truths of social phenomena and of educational policy as a specific object of analysis. In this article I develop a series of propositions about the ways in which field theory might be applied to explain the abrupt public policy shift effected by the Thatcher government and the adjustments made to it by the Blair government. I suggest that a Bourdieuian approach shows policy working as a means of codification, as a doxa of misrecognition and as currency exchange within and across fields. I conclude with some thoughts about the difficulties of explicating interactions between fields.

Colloidal interaction between a rigid solid and a fluid drop

We present results of a theoretical study of the effect of surface deformation on a macroscopic system composed of a solid surface interacting with a fluid drop through electrostatic double-layer forces. The analysis involves numerically solving a Laplace equation suitably modified to describe the shape of a liquid drop subjected to a repulsive double-layer force. The latter is evaluated in nonlinear mean-field theory. Some analytical results are also given. The results indicate that although deformation need not be significant on the macroscopic scale, its effect on the interaction is significant and modifies the picture usually presented in DLVO theory. The decay length of the exponential repulsion deviates marginally from the Debye length, dependent on the interfacial tension of the drop. More significantly, at separations where the double-layer force becomes comparable to the internal pressure of the drop, the net force between the two bodies, the local radius of curvature of the drop, and the amount of deformation grow abruptly. The results of this work are relevant to emulsion stability, micelle, vesicle, and cell interactions, and recent experiments on bubble-particle interaction.

Bourdieu and educational research: thinking tools, relational thinking, beyond epistemological innocence

The main aim of this chapter is to provide an introduction to the theoretical work of Pierre Bourdieu, and to outline different ways in which Bourdieu’s work is influential and has been engaged with in education research and to suggest implicitly the usefulness of this work for educational researchers. In order to do this, we draw on a range of Bourdieu’s own writing published singly or with colleagues, emphasising in particular his engagements with education. Part of our treatment also deals with his wider writing that has subsequently been influential for education researchers, and in particular Bourdieu’s anthropological writing and account of practice (Bourdieu 1977, 1990), his approach to social class and cultural issues, his account of the judgement of taste and distinctions (Bourdieu, 1984), and his later politically focused writing (Bourdieu, 1989/1996, 2003, 2004c, 2005a).

Mediatization and education: a sociological account

This chapter presents an account of the mediatization of education policy through a focus on the development and uptake of the knowledge economy discourse in national education policy and research settings. During the late 20th and early part of the 21st century, Australia, like other nation states around the globe, came to adopt the knowledge economy discourse as a kind of meta-policy that would help connect a variety of statistical indicators and provide direction for a number of policy areas, including education, science, and research funding. In Australia the adoption of a knowledge economy discourse was preceded by coverage from specialized sections of the quality print media, discussed broadly as a debate about the social contract that was afforded to fields charged with developing and producing national capacities for knowledge production. Such a debate mirrored similar claims by Michael Gibbons in the late 1990s, where he argued for a new social contract between science and society. Given the media coverage surrounding the uptake of the knowledge economy discourse and the promotion of the concept by the OECD, this chapter presents an account of the emergence of the knowledge economy discourse through a focus on the mediatization of the concept. The broad argument presented in this account is that what could be called “mediatization effects”, related to the promotion and adoption of policy concepts, are variable, and reach the broader public in inconsistent, time-bound, and sporadic patterns. In order to understand mediatization effects in respect of policy, the paper draws on a broad Bourdieuian informed conceptual framework to understand different kinds of fields, their logics of practice, and importantly here, cross-field effects. Specifically, the focus is on those cross-field effects related to the impact of practices within both national and global fields of journalism on national and global fields of education policy. While the case is an Australian one, the account explores general and more broadly applicable ways to understand links between the globalization and the mediatization of policy.

Aiding journalism: Australian journalism educators and their work in post conflict states

 Dr Wake presents a comprehensive thesis of Australian journalism education and training in the context of foreign aid and policy, particularly as applied in the Solomon Islands. Although it is essentially about journalism, the thesis also adds to the field of development studies. Dr Wake has used Bourdieu’s field theory to underpin her critical analysis.

Impact of front-of-pack 'traffic-light' nutrition labelling on consumer food purchases in the UK

Front-of-pack ‘traffic-light’ nutrition labelling has been widely proposed as a tool to improve public health nutrition. This study examined changes to consumer food purchases after the introduction of traffic-light labels with the aim of assessing the impact of the labels on the ‘healthiness’ of foods purchased. The study examined sales data from a major UK retailer in 2007. We analysed products in two categories (‘ready meals’ and sandwiches), investigating the percentage change in sales 4 weeks before and after traffic-light labels were introduced, and taking into account seasonality, product promotions and product life-cycle. We investigated whether changes in sales were related to the healthiness of products. All products that were not new and not on promotion immediately before or after the introduction of traffic-light labels were selected for the analysis (n = 6 for ready meals and n = 12 for sandwiches). For the selected ready-meals, sales increased (by 2.4% of category sales) in the 4 weeks after the introduction of traffic-light labels, whereas sales of the selected sandwiches did not change significantly. Critically, there was no association between changes in product sales and the healthiness of the products. This short-term study based on a small number of ready meals and sandwiches found that the introduction of a system of four traffic-light labels had no discernable effect on the relative healthiness of consumer purchases. Further research on the influence of nutrition signposting will be needed before this labelling format can be considered a promising public health intervention.

Plane wave scattering by a spherical di-electric particle in motion : a relativistic extension of the Mie theory

Light scattering from small spherical particles has applications in a vast number of disciplines including astrophysics, meteorology optics and particle sizing. Mie theory provides an exact analytical characterization of plane wave scattering from spherical dielectric objects. There exist many variants of the Mie theory where fundamental assumptions of the theory has been relaxed to make generalizations. Notable such extensions are generalized Mie theory where plane waves are replaced by optical beams, scattering from lossy particles, scattering from layered particles or shells and scattering of partially coherent (non-classical) light. However, no work has yet been reported in the literature on modifications required to account for scattering when the particle or the source is in motion relative to each other. This is an important problem where many applications can be found in disciplines involving moving particle size characterization. In this paper we propose a novel approach, using special relativity, to address this problem by extending the standard Mie theory for scattering by a particle in motion with a constant speed, which may be very low, moderate or comparable to the speed of light. The proposed technique involves transforming the scattering problem to a reference frame co-moving with the particle, then applying the Mie theory in that frame and transforming the scattered field back to the reference frame of the observer.